Projection booth port hole blower



March 19, 1957 a. P. HELLER r PROJECTION BOOTH PORT HOLE BLOWER l Filed March 28, 1955 IN V EN TOR.

@orge r? Heller BY @ZAWMW ATTORNEYS.

United States Patent O PROJECTION BOOTH PORT HOLE BLOWER George P. Heller, Kansas City, Mo., assignor to Dit-Meo,

Incorporated, Kansas City, Mo., a corporation of MIS- souri Application March 28, 1955, Serial No. 497,113

2 Claims. (Cl. 98-36) This invention relates to motion picture projection booth blowers and more particularly to a blower arrangement for moving air through the port hole through which the projection beam is directed.

In motion picture theatres, both of the indoor and outdoor type, the projection machines are usually located in a chamber or booth and holes arranged in the walls of the booth and the projection machine lens aligned with the opening or port hole whereby the projection beam will pass therethrough to the screen that is mounted remotely therefrom. Dirt, lint and grease particles normally enter through the port holes in indoor theatres and in outdoor theatres there is additional dust, rain and insects that may enter the port holes. The dust and greasy particles may become deposited on the projection lenses, which lenses are usually of the precision coated type, and said deposits are frequently difficult or almost impossible to remove from said lenses.

The objects of the present invention are to provide a projection booth blower and mounting for directing air across and outwardly through the port hole to eliminate or reduce entry of particles therethrough; to provide a frame defining a passage aligned with a projection booth port hole with a removable closure at the inner end of said passage and a blower directing air into the passage intermediate the length thereof and toward the exterior of the projection booth; to provide such a structure with louvers or battles for distributing the air over the entire cross-section of the port hole passage; and to provide a port hole blower that is economical to manufacture and efficient in operation in eliminating dust, rain, insects and the like from entering projection booths through the port hole thereof.

In accomplishing these and other objects of the present invention, I have provided improved details of structure, the preferred forms of which are illustrated in the accompanying drawings wherein:

Fig. l is a partial perspective view of the interior of a projection booth with the port hole blower and frame mounted on a wall of the booth in alignment with an opening therethrough.

Fig. 2 is a vertical sectional view through the port hole frame.

Fig. 3 is a vertical sectional view through the port hole blower and frame taken on the line 3-3, Fig. 2.

Fig. 4 is a perspective view of the port hole frame enclosure for the passage therethrough.

Referring more in detail to the drawings:

1 designates a motion picture projection booth having a wall 2 provided with an opening 3 aligned with the lens of a projector 4 whereby the projection beam will pass through the opening 2 to a screen (not shown). A port hole frame 5 is suitably mounted on the inside of the wall 2 and defines a tubular passage 6, one end of which registers with the opening 3 in the wall 2.

In the structure illustrated, the frame consists of a bottom wall 7, side walls 8 and top wall 9 with selected 2,785,621 Patented Mar. 19, 1957 ICC walls flanged and suitably secured as by welding to other sure member 15 removably mounted on said flanges for closing the inner opening 12 of the passage 6. The wall 9 has an opening 16 preferably extending substantially from the flange 10 thereon and converging therefrom toward the respective flange 14 for receiving an insert 17.

The insert 17 has a top horizontal wall 18 and downwardly and outwardly sloping side walls 19 and 20, which side Walls extend through the opening 16 and terminate in outwardly directed flanges 21 which underlie and are secured to the portions of the wall 9 adjacent the opening 16, the portion of the wall 18 adjacent the flange 10 being secured to the wall 9. The inner ends of the side walls 19 and 20 are provided with inwardly directed flanges 22 which slope from adjacent the flange 14 upwardly toward the outer end of the frame. The flanges 22 and the inner end of the wall 18 and portion of the wall 9 adjacent the flange 14 cooperate to define an opening 23 for delivery of air into the frame as later described.

A blower 24 preferably of a squirrel cage type is suitably mounted on the frame 5 for directing air through the opening 23. The blower preferably consists of a housing 25 having an inlet opening 26 on one side thereof and a motor 27 mounted on the other side.

The motor is operatively connected to a fan or rotor 28 in the housing whereby operation of the motor drives the rotor, drawing air through the inlet 26 and discharging air through a discharge duct 29. The discharge duct 29 preferably has flanges 30 thereon suitably secured to the flanges 22 whereby the air delivered by the blower is directed through the opening 23 at an angle downwardly and outwardly of the passage 6.

Louvers or baffles 31 are mounted in the discharge duct 29 to distribute the air from the blower over the entire cross-section of the passage 6. In the illustrated structure, there are two louvers or baffles 31 arranged in spaced relation in the discharge connection 29, said louvers preferably having flat portions 32 arranged in planes parallel to the direction of flow of air from the blowers with end portions 33 extending from said connection into the space in the insert 17 above the passage 6, the end portions 33 being curved laterally to deflect a portion of the air flow toward the side walls 8. The lower most corners of the curved portion 33 of the baffle or louvers are cut away as at 34 whereby some of the air is directed downwardly at the sides of the passage 6 and some deflected outwardly to obtain substantial even distribution over the cross-section of the passage 6, all of the air being directed generally outwardly of the passage to provide an air flow and curtain moving outwardly through the opening 2 to blow dust, rain and insects away from the opening and thereby prevent their entry through the port hole.

While the blower is shown as being mounted on the insert 17 in the wall 9, the insert and wall 9 may be made integral and stamped to provide the shape illustrated. Also the bottom wall 7 is shown horizontal and the top wall 9 sloping downwardly and inwardly with the blower at the top of the frame. This arrangement is desirable where the projection beam is angled upwardly towards the screen. In instances where the projection beam would be angled downwardly toward the screen, the frame and blower structure would be inverted.

The blower is operated at all times when the closure 15 is removed from the frame and when it is desired to cease operation of the projection machine, the closure 15 is applied to the flanges 1.4 and moved to close the opening 12. Then the blower operation is stopped. However, the blower should be started prior to removing the closure 15 so that at all times when the passage 6 is open, the air movement will prevent particles and insects from entering the projection booth With this arrangement the projection beam will pass through the port hole without obstruction regardless of the projection angle and entry of particles and insects is substantially eliminated.

What I claim and desire to secure by Letters Patent is:

1. In a motion picture projection booth having an opening in one wall thereof-and a motion picture projector aligned with saidopening whereby the projection beam is directed therethrough, a frame having connected bottom, side and top walls defining a through passage,

means mounting the frame on the projection booth wall with the walls of the frame extending inwardly therefrom and with the passage in the frame substantially aligned with and in registry with the opening in said booth wall, one of said frame Walls having an opening therein adjacent the inner end of said wall, a blower having an inlet connecting with the interior of the booth and a discharge connection, means mounting the blower on the frame with the discharge connection. communicating with the opening in the frame wall and at an angle to the passage in the frame whereby air from the blower is discharged across and outwardly of the passage toward the exterior of the booth, and spaced baflies fixed in the discharge connection, said spaced baffles each having portions in planes parallel to the direction of flow of air through the discharge connection and laterally curved portions adjacent thepassage with the concave sides of said'curved portions toward the side walls of the frame, said laterally curved portions being less than the width of the bafiles and spaced from the edge of the frame opening adjacent the inner end of the frame walls whereby a portion of the air is directed downwardly and outwardly and distributed over substantially the entire cross section of the passage to form a curtain of air moving toward the exterior of the booth and preventing entry of particles through the opening in the wall thereof.

from and with the passage in the frame substantially 'aligned with and in registry with the opening in said booth wall, one of the frame walls. being outwardly embossed with a portion thereof at an acute angle to the passage through the frame, said anguiarly arranged portion having an opening therein, a blower having an inlet connecting with the interior of the booth and a discharge connection, meansv connecting the discharge connection of the blower to the angularly arranged portion of the frame wall and in communication with the opening therein whereby air from the blower is discharged into the passage for flow thereacross and outwardly toward the exterior of the booth, spaced bafiies in the discharge connection adjacent the opening in the angular portion, said spaced bafiles each having portions in substantially parallel planes perpendicular to said angular portion of said one frame Wall and laterally curved portions adjacent said angular portion of said one frame wall with the concave sides of the curved portions toward the frame side walls, said laterally curved portions being less than the width of the baffies and spaced from the edge of the frame opening adjacent the inner end of the frame walls whereby av portion of the air is directed down: wardly and outwardly and substantially evenly distribute the air flow through the passage for preventing entry of insects through the passage into the booth, and a cover means removably mounted on the frame walls at the inner end of-the passage.

References Cited in the file of this patent UNITED STATES PATENTS 774,730, Van Kennel Nov. 8, 1904 1,997,387 McCord Apr. 3, 1935 2,549,042 Angermueller Apr. 17, 1951 2,558,997 Voelker .a July 3, 1951 2,679,972 Brumme June 1, 1954 FOREIGN PATENTS 543,418 France June 2, 1922 835,940 France Oct. 3, 1938 755,299 Germany Mar. 3, 1952 

